The increase in wireless telecommunications traffic has resulted a concomitant incise in the need for pole-mounted transmission equipment of all kinds. Not only do wireless service providers need to install equipment covering new geographic areas, competing service providers and others also need to install additional equipment covering the same or similar geographic areas. To date, the solution to both problems normally includes purchasing additional land or easements, applying for the necessary government permits and zoning clearances, and constructing a new tower for the new transmission equipment.
Purchasing land or easements, however, is becoming increasingly expensive, particularly in urban areas where the need for wireless telecommunications is greatest. Zoning regulations often limit the construction of new towers in the vicinity of existing towers or may prohibit the construction of new towers in the most suitable locations. The expense and delay associated with the zoning process often may be cost-prohibitive or so time-consuming that construction of the new tower is not feasible. Even when zoning regulations can be satisfied and permits can be obtained, the service provider must then bear the burden and expense associated with the construction and the maintenance of the tower.
The tower itself must be designed to support the weight of the telecommunications transmission equipment as well as the forces exerted on the pole by environmental factors such as wind and ice. The equipment and the environmental factors produce forces known as bending moments that, in effect, may cause a single-pole tower to overturn if not designed for adequate stability. Traditionally, single-pole towers have been designed to withstand the forces expected from the equipment originally installed on the pole. Very few single-pole towers, however, are designed with sufficient stability to allow for the addition of new equipment.
Thus, there is a need for a method and an apparatus for increasing the capacity and stability of a single-pole tower that will support the weight of additional equipment and support the additional environmental forces exerted on the pole. At best, the prior art shows various brackets used for restoring the strength of a weakened or damaged section of a wooden pole. An example of a known pole restoration system is shown in U.S. Pat. No. 4,991,367 to McGinnis entitled, “Apparatus and Method for Reinforcing a Wooden Pole.” This reference describes an apparatus that employs a series of braces linked together around the circumference of a tapered pole. The braces are then forced downward on the pole to wedge the assembly tightly against the pole to provide support. This system does not include an anchorage to the ground or base of the pole.
A number of other known pole restoration systems employ a first part attached to the damaged section of the pole and a second part that is driven into the ground to provide support. An example of such a system is shown in U.S. Pat. No. 4,756,130 to Burtelson entitled, “Apparatus for Reinforcing Utility Poles and the Like.” This apparatus uses a series of brackets and straps attached to ground spikes. Another example of a known pole restoration system is shown in U.S. Pat. No. 4,697,396 to Knight entitled, “Utility Pole Support.” This reference describes an apparatus with a series of brackets attached to a wooden utility pole. A series of tapered spikes are anchored on the brackets and then driven into the ground to provide support. Additional examples of such a system are shown in U.S. Pat. Nos. 5,345,732 and 5,815,994, both issued to Knight & Murray, entitled “Method and Apparatus for Giving Strength to a Pole” and “Strengthening of Poles,” respectively. These references describe an apparatus with a nail or bridging beam driven through the center of the wooden pole. The nail is attached by linkages to a series or circumferential spices that are then driven into the ground to provide support.
In each of these systems, the brackets are fixably attached to a damaged wooden utility pole to provide a firm anchor for the ground spikes. The spikes are driven into the ground immediately adjacent the pole to wedge the spike tightly against the side of the pole. The functionality of each of these systems depends, therefore, on the rigid attachment between the pole brackets and the spikes as well as the compression fit of the spikes between the ground and the pole. Further, these ground-based systems only function when the damaged pole section is sufficiently near the ground for the bracket assembly to be attached to the ground spikes. The capacity of these known systems to resist bending moments is dependent upon the height of the damaged section relative to the ground as well as the characteristics of the soil and other natural variables. Moreover, each of these systems describes an apparatus for the purpose of restoring a damaged pole to its original capacity, not for the purpose of bolstering an existing pole to increase its capacity.
Thus, there remains a need for a method and apparatus for increasing the capacity and stability of a single-pole tower that will support the weight of additional equipment and support the additional environmental forces exerted on the pole, while providing sufficient stability to resist the forces known as bending moments exerted by the new equipment and the environmental forces. Such a method and an apparatus should accomplish these goals in a reliable, durable, low-maintenance, and cost-effective manner.